DAVID A. GRAHAM. "Soon after coming to power, the Bolsheviks printed the text in Pravda—not the last time the Russians would play spoiler to Western efforts to control events in Syria and Iraq.​Monday marks the 100 years since the signing of the Sykes-Picot Agreement, the secret Anglo-French pact reached during the First World War that proposed splitting the Middle East up into zones of foreign control. The Middle East has been frequently afflicted with war since then, but the situation now—with ISIS holding territory in Iraq and across the Fertile Crescent, civil war in Syria, government paralysis in Lebanon, growing autocracy and violence in Turkey, and talk of an intifada in Israel and the occupied territories—has inspired particular debate on the century-old agreement’s legacy. Laments about Sykes-Picot drewarbitrary divisions that bedevil the Middle East even now have met with just-as-impassioned insistence that the secret agreement’s influence is overstated.

But wait a second: secret agreement? How did a confidential document become a hotly contested matter of the public record not long after it was signed? The answer is a tale of intrigue that serves as a reminder of how unstable closed-door diplomacy is, and how fast quiet handshakes can cause public backlash, even in the age before Wikileaks.